Internal combustion engines are used in a wide variety of stationary as well as mobile applications. Internal combustion engines may include either spark ignition engines or compression ignition engines. Stationary internal combustion engines used for air compressors or electrical power generation are frequently used in mining operations in chemical plants or military installations. In such applications, conditions may exist that require an engine control system to shut down the engine. For example, if the engine coolant temperature exceeds a threshold the engine should be shut down. Engines operating in particular applications such as environments having hazardous combustible gases or fire pump applications are required to meet certification requirements to ensure safe operation. Such engines may be required to have an engine shutdown control system.
Engines operating in hazardous environments require certification for their specific environment. For example, hazardous environment applications may be categorized as Group II zone 2 or class 1 division 2. Hazardous environment applications typically require a redundant engine shutdown system in addition to the standard engine shutdown system that is available on most, if not all, commercially available electronically controlled engines. For example, standard EN 1834-1 “Reciprocating internal combustion engines—Safety requirements for design and construction of engines for use in potentially explosive atmospheres—Part 1: Group II engines for use in flammable gas and vapor atmospheres” and the ATEX directive require a redundant engine shutdown system. To meet this standard it has been proposed to use the engine controller as a shut down system, however, this approach does not meet all requirements for an engine shutdown system under the standard.
The above problems are addressed by Applicants' invention as summarized below.